1. Field of the Invention
This invention relates to a method of decoding in run representation, and more particularly to a method of decoding in run representation for use in image processing in OCR (optical character recognition) apparatus, image communication apparatus, and image processing apparatus or the like.
2. Description of the Prior Art
Run representation is a well-known method of representing images. A run unit is defined as a unit in which black pixels or white pixels are continuously present when images are raster-scanned horizontally or vertically. Run representation is a method of representing images by the use of a run unit as a smallest unit. In run representation, images are represented in accordance with information on the run lengths or positions of run units. Run representation can advantageously represent original images with less information than the information required to represent bit patterns. Therefore, run representation has been utilized as a data compression technique.
However, run representation generally has a problem in that inordinate time is required to obtain the bit patterns of original images by decoding the run unit in which the original images are encoded. Conventionally, in the case of a FAX, this problem has been avoided by performing high-speed decoding with additional hardware. However, when only software is utilized in the decoding process, this problem previously could not be avoided.